Faraday cage

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A container made of a conductor, such as wire mesh or the metal frame of an aircraft, forming an equipotential shield around what it encloses and protecting it from external electric fields.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any conductive surrounding, idealized or practical, used to interrupt the transmission of electromagnetic energy or electrostatic discharge across it.